Many users have duplicate racks of a base system. For example, "My Current Rack", "My Future Rack", "My Future Future Rack", etc.

Rather than making multiple racks, let users tag the modules in their base rack as "current", "future", "next", "drumwish", "2016", etc.
A toggle that switches between those variants then would dim the modules not having the tag corresponding to the toggle setting.

Not sure if this would work in every way. Users tend to reposition modules when their systems change to fill up the gapes.

I agree because I reposition mine as well, but it would be an inconvenience of minor significance when compared to the benefits. In my case the repositioning would be viewed as not that desirable.

But "repositioning" could be further achieved by another toggle corresponding to state. If one so desired.

Both options are much more logically sensible than the current implementation of "clone my entire rack, add a few modules, rinse and repeat", which adds noise to redundancy.

I like the idea of having multiple states for a rack.

Especially when trying different module positions within a rack.
I do a lot of copies just to re-shuffle some modules. Having several states would be great in this context.
I suppose this should be easier to implement as the initial request to have different modules for the same rack.
What i ask for relates to the same set of modules, just different "coordinates" for them in the rack.

EDIT: I just realise this may have a bad impact on selling Unicorn accounts, because users do not need multiple racks to try out variations anymore. Just make it Unicorn only :) Another good reason to go "pro" hehe

A Eurocrack Pusher: "The first time is for free" ;)

I am still not sure where the benefit of multiple states is or what is overall different in comparison to just copy a rack?